There is described in the literature the use of a number of compositions for reducing the interbonding effect of ice formation between particulate materials. In U.S. Pat. No. 4,117,214 to Parks and Nimerick, there is described the use of a composition of (a) water-soluble polyhydroxy compound or monoalkylether thereof and (b) a water-soluble organic nonvolatile compound having a hydrophilic group, such as amine, carboxyl or carboxylate, in an amount which is effective to weaken the physical integrity of ice when added to water prior to its being frozen. Such a composition can be applied to inorganic particulate masses which contain water and when the masses are subjected to freezing conditions, the composition becomes incorporated into the ice formed and renders the ice physically weak when the mass has to be separated. This can be demonstrated by the fragility imparted to an ice cube, see Procedure (A), infra. The patent, in particular, is concerned with the treatment of coal placed in hopper cars so that when coal is transported under freezing weather conditions, the ice does not adversely affect one's ability to remove the coal from the hopper cars. In this respect, the patent refers to an article in Business Week, Feb. 14, 1977, pages 32-34, to characterize the severity of the freezing problem as it applies to the transportation of inorganic particulate materials, in particular, coal.
The particular composition which this patent indicates to be the most desirable for use in the treatment of coal subjected to freezing weather conditions is a blend of 47.5 wt. % ethylene glycol, 47.5 wt. % propylene glycol, and 5 wt. % sodium acetate. The patentees also describe in broader terms the kind of composition which they regard as capable of affecting the cohesive strength of ice formed about solid particulate materials. One of the ingredients, according to the patent, is a polyhydroxy alkane and typical members of that class are ethylene glycol, diethylene glycol, glycerine, and sugar. Of those, ethylene glycol is indicated as preferred. In addition, the patentees mention that a mixture of those glycols may be employed as a first component of the total composition and illustrative of that is a mixture such as ethylene glycol and 1,2-propylene glycol. The second material which is used in the composition for treating the particulates is a "water-soluble organic nonvolatile compound". Although this compound is extremely broadly defined, the specific illustrations set forth in the patent are materials such as fumaric acid, urea, glycolic acid, tetrasodium salt of ethylene diamine tetraacetic acid, sodium acetate and acetic acid. The polymeric materials described are polyacrylamide, polyvinyl pyrrolidone, polyethyleneimine, polyacrylates, polyamide copolymers, such as that sold commercially as Arco S-232, and the natural gums, such as guar gum.
A factor in distinguishing the process of U.S. Pat. No. 4,117,214 from what had been utilized in the prior art in ice treatments involves the quantity of the treating agent that the patentees supply to the particulate mass to prevent the kind of ice formation which precludes the breaking apart of a particulate mass. The patentees use less of the treating agent than is normally employed in antifreeze conditions or in deicing situations.
The compositions of this invention can impart a higher degree of fragileness to ice formed in the particulate mass than the compositions described in U.S. Pat. No. 4,117,214 and the instant composition represents an improvement over said prior art composition. Also, the compositions of this invention have a lower viscosity than the compositions described in U.S. Pat. No. 4,117,214. This lower viscosity facilitates spraying the compositions onto the particulate matter. The lower viscosity also permits greater penetration of the compositions into the particulate matter, such as coal.